In a steering column of an automotive vehicle, a lower bearing assembly supports the steering shaft for rotation. In the case of cylindrical steering shafts, a spring is provided to keep the load on the bearing.
The present invention applies to a so-called double-D steering shaft which has two diametrically opposite, arcuate sides, and two diametrically opposite flats between the arcuate sides. In accordance with a preferred embodiment of the invention, the steering shaft extends through a cup in the jacket surrounding the steering shaft and an annular bearing sleeved on the steering shaft at the base of the cup supports the steering shaft for rotation. The bearing is held seated in the base of the cup by a wedge sleeved on the steering shaft having a tapered nose or wedge which is wedged between the bearing and the steering shaft. The wedge has an internal double-D configuration matching that of the steering shaft. A compression coil spring encircling the wedge bears against a flange on the wedge to hold the nose of the wedge wedged tightly between the bearing and the steering shaft. A retaining ring is sleeved on the steering shaft and holds the spring under compression. The construction also preferably includes a spacer between the wedge and the retaining ring, the retaining ring bearing against the spacer and the spacer bearing against the spring.
Further in accordance with the invention, the retaining ring preferably has an inner configuration which matches that of the double-D steering shaft. It is formed with two diametrically opposite, arcuate side edges to frictionally engage the arcuate side walls of the steering shaft. The retaining ring is also formed with two diametrically opposite, parallel, straight edges which frictionally engage the two flat sides of the steering shaft. Preferably, the retaining ring has an annular base formed with two diametrically opposite, arcuate flanges bent to an acute angle relative to the base and terminating in the arcuate side edges which engage the curved sides of the steering shaft. The base is otherwise flat between the flanges and terminates in the straight edges which engage the flat sides of the steering shaft.
One object of this invention is to provide a lower bearing assembly having the foregoing features and capabilities.
Another object is to provide a lower bearing assembly which is rugged and durable in use and capable of being readily and inexpensively manufactured and assembled.
These and other objects, features and advantages of the invention will become more apparent as the following description proceeds, especially when considered with the accompanying drawings.